Impulse-induced compression rheo-optics study of polymers using attenuated total reflection based step-scan Fourier...

Area of Science:

• Materials Science
• Polymer Science
• Spectroscopy

Background:

• Understanding polymer viscoelasticity is crucial for material design and application.
• Traditional methods may not capture rapid or complex relaxation dynamics.
• Fourier transform rheo-optical spectroscopy offers a powerful approach to probe material responses.

Purpose of the Study:

• To develop and validate an impulse-induced attenuated total reflection (ATR) based dynamic compression step-scan time-resolved Fourier transform rheo-optical system.
• To investigate the viscoelastic properties of poly(ethylene terephthalate) (PET), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHx), and a carbon-black-filled polyester-polyamide blend.
• To demonstrate the system's capability in characterizing diverse viscoelastic materials.

Main Methods:

• Development of a novel rheo-optical system combining ATR, dynamic compression, and step-scan time-resolved Fourier transform infrared spectroscopy.
• Application of the system to analyze the dynamic absorbance difference spectra of PET, PHBHx, and the blend under impulse compression.
• Analysis of relaxation times and spectral features, particularly in the C=O stretching band region.

Main Results:

• Poly(ethylene terephthalate) (PET) exhibited minimal viscoelastic response beyond 15 ms.
• Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHx) showed a distinct relaxation tail of approximately 2.7 ms, attributed to the reorganization of less ordered crystalline forms.
• The carbon-black-filled blend displayed unique viscoelastic responses, with the polyamide component showing limited contribution to the observed properties.

Conclusions:

• The developed rheo-optical system effectively captures dynamic viscoelastic responses in polymers.
• The study highlights differences in viscoelastic behavior among PET, PHBHx, and polymer blends.
• This method shows significant potential for characterizing a broad range of viscoelastic materials, including semicrystalline polymers, blends, and composites.